The massive unamed tunnel demon was in a plot alongside Jinmen and another female demon named Aleda where a train would leave its station but at the first tunnel it comes across the Tunnel Demon would swallow the train, then Jinmen and Aleda would devouer all the passengers inside. One train that the Tunnel Demon swallowed was the 16:10 Shinkansen which the young girl Sachiko was useing after meeting up with her freind Akira Fudo.